Squid is a high-performance proxy caching server for web clients,
supporting FTP, gopher, and HTTP data objects. Unlike traditional caching
software, Squid handles all requests in a single, non-blocking, I/O-driven
process.

Squid keeps meta data and especially hot objects cached in RAM, caches DNS
lookups, supports non-blocking DNS lookups, and implements negative
caching of failed requests.

Squid supports SSL, extensive access controls, and full request logging.
By using the lightweight Internet Cache Protocol, Squid caches can be
arranged in a hierarchy or mesh for additional bandwidth savings.
